Mobility Pattern Aware Routing for Heterogeneous Vehicular Networks Chia-Chen Hung∗, Hope Chan†, and Eric Hsiao-Kuang Wu∗ ∗ Dept. of Computer Science and Information Engineering, National Central University, Chung-Li, Taiwan, R.O.C. † Network & Multimedia Institute, Institute for Information Industry, Taiwan, R.O.C. 69821004 黎引得 69821038 陳 靖
Outline • Introduction • Background • Mobility Pattern Aware Routing(MPAR) for Heterogeneous Vehicular Network(HVN) • Performance Evaluation • Conclusion
Introduction • Several wireless network technologies (e.g. VANET, WMAN) that support V2V and R2V service can be applied to the communication system of the ITS. • Reliable data transmission challenges • High mobility of vehicle • Geographic restriction • Traffic density
Introduction • In this paper, we propose a Heterogeneous Vehicular Network (HVN) architecture that integrates the advantages of the WMAN and VANET. • The Mobility Pattern Aware Routing Protocol (MPARP) for HVN to provide more reliable V2V service.
Background A. WMAN and VANET technology • WMAN <R2V:802.16> • High capacity (15Mbps) • Different types of quality services • Larger transmission range (15km) • VANET <V2V:802.11p> • Data rates of 6Mbps • communication distance to 300m
Background B. Ad Hoc Network and Routing Protocols • Topology based routing • Proactive (e.g. DSDV) • On-demand routing(e.g. DSR, AODV) • Position-based routing • e.g. GPSR C. Heterogeneous Wireless Network • Cellular network (WWAN), WMANs, WLANs, and WPANs
Mobility Pattern Aware Routing for Heterogeneous Vehicular Network • Heterogeneous Vehicular Network (HVN) Architecture • Proposed Routing Algorithm
Proposed Routing Algorithm 1) Message Format 2) Routing Metrics 3) Routing Maintenance 4) Dependent Vehicular Group (DVG) 5) Terminology 6) Mobility metrics
1) Message Format • Position update message: • <vehicle id, current position of the vehicle (x,y), current speed of the vehicle (Vx ,Vy))> • Route request message: • <vehicle id, target vehicle id> • Route reply message: • <route path, route valid indicator> • Route refresh message: • <revised route path, route valid indicator>
2) Routing Metrics 802.16 802.11 BS VS VT DVG T F B
3) Routing Maintenance 802.16 802.11 BS VS DVG F T
4) Dependent Vehicular Group (DVG) • The basic idea of DVG is to check whether vehicles on the route path can construct a vehicular group which has higher average degree of spatial dependency , higher average degree of temporal dependency and lower relative speed (RS).
5)Terminology • RD(v1(t1), v2(t2)): relative direction between the two velocity vectors • SR(v1(t1), v2(t2)): speed ratio between the two velocity vectors • R: transmission range of an 802.11 interface • N: number of vehicles in DVG. • Di,j(t): distance between vehicles i and j at time t.
6) Dependency • Average degree of spatial dependency: Dspatial(i, j, t) = RD(vi(t), vj(t)) ∗ SR(vi(t), vj(t)) Di,j(t) > c1 ∗ R ⇒ Dspatial(i, j, t) =0. P is the number of tuples (i, j, t) such that Dspatial(i, j, t) 0
6) Dependency • Average degree of temporal dependency Dtemporal(i, t1, t2) = RD(vi(t1), vi(t2)) ∗ SR(vi(t1),vi(t2)) • where P is the number of tuples (i, t1, t2) such that Dtemporal(i, t1, t2) 0.
6) Dependency Relative speed: RS(i, j, t) = If we get the relative speed, we can calculate the link lifetime between two vehicles as below: Link lifetime:
Performance Evaluation • Simulation model
Heterogeneous Vehicular Network(HVN) Communication Scenario
Conclusion • In this paper, we introduce a newHeterogeneous VehicularNetwork (HVN) architecture and propose a Mobility Pattern Aware Routing Protocol (MPARP) which well suites for highdynamic vehicular network environment. • The simulation resultsshow that MPARP can provide the reliable route path forV2V communication.
討論問題 • 1.環境太過簡單理想化 • 2.既然有BS輔助傳輸，那何必需要點對點傳輸直接用BS傳送不是比較快？且鍊節的穩定度方面也比較好？ • 3.在國外荒郊野外，到一個沒有BS的地方，該怎麼辦?